I agree they shouldn't of left, simply because the numbers just aren't there anymore. I can't think of any other top team with 2 midfielders in the first team squad (3 if you include Lampard, who looks like being weeks away from going).
I've no problem in letting Essien and Meireles go if they were replaced by younger players, but that didn't happen. Personally i'd like to see Newcastle start doing well, Cabaye is out till next year so maybe if Anita and Tiote form a nice partnership they could be tempted to let him leave for the right price. It was amazing they held on to all of their big players last summer, something has to give, especially when you hear Ashley wants to bring in the likes of Debuchy, Sissoko, Granqvist and Remy.